Accession Number : AD0778955

Title :   Wave Breakdown and Turbulence.

Descriptive Note : Interim rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF AERONAUTICS AND ASTRONAUTICS

Personal Author(s) : Landahl,Marten T.

Report Date : DEC 1973

Pagination or Media Count : 45

Abstract : Some new ideas on the dynamics of shear flow turbulence are presented. Central to these is the phenomenon of wave breakdown. This is defined as the onset of a violent small-scale secondary instability developing on a large-scale primary disturbance of wave-like traveling type. It is suggested that breakdown together with the ensuing violent mixing process (a turbulent 'burst') constitutes the dominant nonlinear mechanism for the fluctuating velocity field in a turbulent boundary layer. A burst regeneration mechanism is proposed whereby one breakdown can excite large velocity defects in the shear flow which then may trigger a new breakdown, thus leading to self-maintenance of the turbulence. (Author)

Descriptors :   *Turbulent boundary layer, *Shear properties, *Waves, Disintegration, Secondary flow, Dynamics, Turbulent diffusion

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE